These reliefs give you a good idea of how that period looked like. Many architectural, clothing, etc references in these reliefs.

These reliefs are made in the Satavahana period, but the Satavahana being one of the Mauryans successors carried on many of it's style. The Mauryans would've made these carvings on wood. Sungas, Satavahana, etc started/shifted to use stone more.

The discoveries at Sisupalgarh are quite similar as described in the Arthasastra.
Translations from the Arthasastra about the description of fortified town are
given in the following passages.
"â€¦ the king may have his fortified capital as the seat of his â€¦.in a locality
naturally best fitted for the purpose. Such as the bank of the confluence of the
rivers, a deep pool of perennial water or a lake or a tank, surrounded with an
artificial canal of water connected with both land and water paths."
" Above the rampart, parapets in odd or even numbers and with an intermediate
space from 12-24 hastas from each other shall be built of bricks."
"Demarcation of the ground inside the fort shall be made first by opening three
royal roads from west to east and three from South to northâ€¦"
These references from the Arthasastra are corroborated by Archaeological
findings at Sisupalgarh e.g
The presence of a square (Chaturasara) settlement.
Fortification walls oriented along the cardinal directions.
A moat around the fortification fed by a perennial stream.
The fortification comprising a rampart and over lying brick walls
with intermediary earthen fillings.
Three royal roads running east-west and north and south
So far there are two differences:6
There are two major roads in east-west and north-south direction.
May be due to Sisupalgarh not being as large a settlement as
envisaged in the Arthasastra.
The Arthasastra describes about twelve major gateways where as
Sisupalgarh has only eight.
The fort forms Rough Square in plan. The outline clearly suggests the existence
of corner towers and eight large gateways, two on each sides besides about eight
smaller openings distributed all over the perimeter. The gateways are so placed
that if the distance between the two corner towers of any side is trisected, a
gateway will be found near each point of trisection. All these suggests a regular
planning not only of the fortification but of the streets inside which are likely to
have run east-west, north-south connecting the opposite gateways in a grid
pattern.
An assemblage of 16 monolithic pillars, locally called Shola Khamba in an area
of some 30 m x 30 m near the centre of the fortress were of special interest. Built
up of laterite, some pillars are bearing medallions like those found in Bharhut,
Sanchi, Udayagiri and Khanadagiri caves. The columns measure over 4.9 m in
height and have a maximal diameter of about 70 cm. This could be the remains
of a pillared hall since the pillars have horizontal sockets, seemingly intended to
hold superimposed beams or rafters. However only few pillars are standing intact
while others are missing their upper portion. The ground level inside the fort is
4.5 meter higher than outside. The fort while being too large for a mere citadel
enclosing perhaps the kingâ€™s palace and attached residence or quarters, did not
seem to accommodate common people, most of whom lived outside its confines
as it appears from the pottery remains towards the north and the west.

Excavation has revealed that the fort was in occupation from the beginning of the
third century BC till the middle of the fourth century AD. It also suggests that the
culture of the site had reached its height in the early phase i.e., 200 BC to 100
AD. And the deterioration had started taking place around 100 AD to 200 AD.
Originally the defences were constructed towards the beginning of 200 BC and
consisted of massive mud ramparts,10.12 meters wide at the base and more than
8 meters high with magnificent gateways, guard rooms, ancillary passages and
corner towers. In the second phase the clay rampart being susceptible to erosion
was reinforced by adding a thick layer of gravel in its top. The third phase is
marked by the erection of two brick walls, eight meters apart on top of the gravel
layer with fillings of mud and debris in between. Finally a collapsed revetment
wall was renovated with a battered exterior. The city was systematically planned
with well built houses of laterite or brick laid out in orderly streets in a grid
pattern. Cart-tracks uncovered at various levels of the streets reveal a record of
life of the people in the city.
The excavated western gateway of Sisupalgarh is worth mentioning. Built up of
large slabs of dressed laterite this gateway is remarkably elaborate. The imposing
complex has a passage 8mts wide between two flank walls and two gates, outer
and inner, giving access to the interior of the town. Immediately behind the outer
entrance a guard room was built in the southern flank while in northern flank
near the inner gate was pierced by narrow pathway for pedestrian traffic
probably a bypass when the main gate is closed. There were steps ascending

Water resource is the deciding factor for town planning. Sanskrit and Pali
literatures as well as Vastusastras exhibit moat, ditch or natural water barriers as
safety valve of defense for the fort or the capital city. The moats though planned
for defensive measure in the past, served as well for the water source for the
township. Sisupalgarh is circumscribed by the water streamlet called the
Gangua. The flow of the water is around the north, east and western sides of the
fort, thus producing a moat with perennial supply of water. The houses inside the
fort have wells fed by percolating water of the moat.
It was while excavating the site of Sisupalgarh to find out the culture sequence of
rouletted ware that fortunately along with the rouletted ware an excellently laid
out fort of the pre-Christian era was unearthed by Prof. B. B.Lal in 1948. Soon
after the Archaeological Survey of India ( ASI) declared the site protected in
February 13, 1950 with the caption: "Ancient remains inside and outside rampart
mostly buried". ASI has also recommended the site be declared protected for
excavation. Organisations like Indian National Trust for Art and Cultural
Heritage (INTACH) and Orissa Development Studies (ODS) had come forward
with similar demands.

These images are from the Mauryan ruins of a hypostyle 80-pillared hall. From Pataliputra.

Kumhrar, is the site of the ancient city of Patliputra, lies 5 kms from Patna railway station. Archaeological findings in this area establish Patna's claim to over a thousand years of political glory - 600 BC to 600 AD. The place contains the ruins of the ancient city Patliputra. Very little of this grandeur remains though, except for the remains of a huge Mauryan hall supported by 80 sandstone pillars datingback to 300 BC.

Who destroyed India's ancient past? Who wanted to eliminate any reference of past Glory of India and replace it by its own that too it was never its own? Who destroyed ancient Universities and Temples which were centers of learning and science? Who used to cut nose of Idols of Gods and Goddesses? Who never shows any respect for other religions or human lives? Ask any question and the answer remains same!